Semiconductor processing methods of forming self-aligned contact openings

ABSTRACT

Semiconductor methods of forming self-aligned contact openings are described. In a preferred implementation, a conductor is formed over a substrate. A first layer of material is formed over the conductor. A second layer of material is formed over the first layer of material. The first and second layer materials can be etchably different. Portions of the first and second layers are then removed to form a contact opening to the conductor. According to one aspect, the second layer material is removed at a slower rate than the rate at which first layer material is removed. According to another aspect, portions of such layers are removed at the same time. According to still another aspect of the invention, the second layer material comprises a sacrificial spun-on material.

TECHNICAL FIELD

This invention relates to semiconductor processing methods of formingcontact openings.

BACKGROUND OF THE INVENTION

One aspect of semiconductor processing involves making contact to orelectrical connection with integrated circuitry devices, such asconductors or conductive lines which underlie one or more layers ofmaterial provided over a substrate. One prior art method of making suchconnection utilizes contact pads. These are enlarged conductive areaswhich are typically rectangular or square in shape and operablyconnected with the integrated circuitry device with which electricalconnection is desired. The enlarged pad area provides a degree oftolerance for mask misalignment to still achieve the desired contactwithout causing an electrical short with other adjacent circuitry. Thelarger contact pad areas, however, consume valuable wafer surface areawhich could desirably be used for additional circuitry.

The problem is exemplified in FIG. 1, where a portion of an integratedcircuit is indicated generally at 10. Integrated circuit 10 comprises asubstrate 11 atop which a conductor 12 is formed. An insulative layer 13is provided over conductor 12 and corresponding substrate surface areaadjacent the conductor. A contact opening 14 of a minimum desireddimension is formed through a photoresist layer 19, but because it isslightly misaligned to the left, a corresponding portion of insulativelayer 13 directly overlying substrate 11 is undesirably removed. Suchcan also result in etching into substrate 11, as shown.

One prior art proposed solution is set forth in FIGS. 2 and 3. There, aportion of integrated circuitry 10a includes an insulative orsemiconductive substrate 11 having an enlarged contact pad 15 formedthereon. A conductive line 16 is formed over substrate 11 and connectswith contact pad 15. The goal is ultimately to make electricalconnection with line 16.

An insulative layer 17 is formed over contact pad 15. A contact opening18 is targeted to be etched to contact pad 15. As shown, contact pad 15is made considerably larger than the resultant contact opening 18 toprovide a tolerance for contact mask misalignment. As an example, tworepresentative contact mask misalignments are shown (FIG. 2). A firstcontact mask misalignment is shown in dashed lines at 20 and representsa lateral and rotational displacement of the contact opening from thedesired central location shown in solid lines. A second contact maskmisalignment is shown in dash-dot lines at 22 and represents a simplemisplacement in the negative x-direction. Either way, the contactopening falls within the boundary of the contact pad and the desiredelectrical connection is made. Accordingly, the wider-dimensionedcontact pad tolerates mask misalignments, but at the expense ofconsuming precious wafer real estate.

This invention grew out of concerns associated with conserving waferspace or area. This invention also grew out of concerns associated withreducing or decreasing the area required for a contact pad.

SUMMARY OF THE INVENTION

Semiconductor methods of forming self-aligned contact openings aredescribed. In a preferred implementation, a conductor is formed over asubstrate. A first layer of material is formed over the conductor. Asecond layer of material is formed over the first layer of material. Thefirst and second layer materials can be etchably different. Portions ofthe first and second layers are then removed to form a contact openingto the conductor. According to one aspect, the second layer material isremoved at a slower rate than the rate at which first layer material isremoved. According to another aspect, portions of such layers areremoved at the same time. According to still another aspect of theinvention, the second layer material comprises a sacrificial spun-onmaterial.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

FIG. 1 is a diagrammatic view of a prior art contact opening and isdiscussed in the "Background of the Invention" section.

FIG. 2 is a diagrammatic view of a prior art contact pad and isdiscussed in the "Background of the Invention" section.

FIG. 3 is a view taken along line 3--3 in FIG. 2.

FIG. 4 is a diagrammatic sectional view of a semiconductor waferfragment at one processing step in accordance with the invention.

FIG. 5 is a view of the FIG. 4 wafer fragment at a processing stepsubsequent to that shown in FIG. 4.

FIG. 6 is a view of the FIG. 4 wafer fragment at a processing stepsubsequent to that shown in FIG. 5.

FIG. 7 is a view of the FIG. 4 wafer fragment at a processing stepsubsequent to that shown in FIG. 6.

FIG. 8 is a view of the FIG. 4 wafer fragment at a processing stepsubsequent to that shown in FIG. 7.

FIG. 9 is a view of the FIG. 4 wafer fragment at a processing stepsubsequent to that shown in FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This disclosure of the invention is submitted in furtherance of theconstitutional purposes of the U.S. Patent Laws "to promote the progressof science and useful arts" (Article 1, Section 8).

Referring to FIG. 4, a conductor assembly to which electrical connectionis to be made is indicated generally at 24. The illustrated conductorassembly 24 comprises a semiconductive substrate 25, such as a bulksilicon substrate, and a substrate insulator or insulative layer ofmaterial 26. Substrate insulator or insulative layer of material 26typically constitutes a thin oxide material which is formed over thesemiconductive substrate. Material layer 26 includes a substrate outersurface 28. Other substrate constructions are possible. In the contextof this document, the term "semiconductive substrate" is defined to meanany construction comprising semiconductive material, including, but notlimited to, bulk semiconductive materials such as a semiconductive wafer(either alone or in assemblies comprising other materials thereon), andsemiconductive material layers (either alone or in assemblies comprisingother materials). The term "substrate" refers to any supportingstructure, including, but not limited to, the semiconductive substratesdescribed above.

A conductive structure 30 is formed over substrate outer surface 28 andincludes at least one abrupt topological feature relative to a laterallyspaced adjacent substrate surface. In the illustrated and preferredembodiment, conductive structure 30 comprises one or more polysilicon orpolycide layers, with such layers being typically formed elevationallyover and in close proximity with other conductors or devices. It isdesirable when forming an electrical connection with conductivestructure 30, to avoid making electrical connection with otherconductors or devices elevationally thereunder. In the illustratedexample, such other conductors or devices (not specifically shown) wouldtypically underlie material layer 26. Conductive structure 30 includes aplanar outer surface 32 which is generally elevated relative toimmediately laterally adjacent substrate surface 28. Conductivestructure 30 includes two abrupt topological features in the form ofsidewalls or sidewall edges 34, 36 which extend between outer surface 32and adjacent substrate surface 28. Such supports surface area 32elevationally outwardly of substrate outer surface area 28. Topologicalfeatures other than the illustrated sidewalls are of course possible.

Sidewalls 34, 36 constitute conductive surfaces which extend generallyoutwardly of and away from the laterally adjacent substrate surface.Outer surface 32 accordingly defines a preferably planar conductortarget surface having two sidewalls 34 and 36 joined therewith at edges38 and 40, and which extend preferably transversely away therefromtoward the adjacent substrate surface 28. Outer surface 32 is therebydisposed between edges 38 and 40. Sidewalls 34 and 36 constituteconductor surfaces (other than surface 32) which are elevationally belowedges 38, 40. Conductor 30 defines a width dimension W in a widthdimension direction which lies in the plane of the page and betweenedges 38, 40.

A first layer 42 is formed over conductor 30 and adjacent substrateouter surface 28. Layer 42 preferably covers the conductor and isinsulative or dielectric in nature, forming a unitary and generallyconformal insulative material layer over the conductor. Layer 42 neednot, however, be conformal. Preferably, first layer 42 is formed to anelevational thickness over the conductor outer surface area 32 of fromabout 50 Angstroms to about 5000 Angstroms. Example materials for firstlayer 42 include doped or undoped SiO₂, Si₃ N₄, Al₂ O₃, TiO, a layerwhich is formed from decomposition of tetraethyl orthosilicate (TEOS),and the like.

A second layer 44 is formed over first layer 42. Second layer 44 has anon-uniform elevational thickness relative to first layer 42.Accordingly in the illustrated and preferred embodiment, second layer 44takes on the appearance of a mound of material which is formed overconductor 30 and layer 42. Preferably, second layer 44 is formed ormounded over first layer 42 and conductor 30 by spin coating the secondlayer onto substrate 26. Accordingly, the second layer of materialaccumulates to a thicker degree in the vicinity of sidewalls 34, 36 andthe portions of first layer 42 thereadjacent. Such provides a secondlayer which has a variable elevational thickness relative to theunderlying dielectric material layer 42. Such is effectuated at least inpart by the abrupt topology of the conductor sidewalls 34, 36 whichserves to enable a desired amount of second layer material to accumulatethereover when applied in the preferred manner. Accordingly, secondlayer 44 is generally non-conformal and has a varying elevationalthickness relative to substrate surface 28. Layer 44 is preferablythinner elevationally outward of outer surface 32 and thicker laterallyadjacent conductor 30. In a preferred implementation, layer 44 tapersgenerally toward the substrate surface as the layer extends laterallyoutward of sidewalls 34, 36.

Example materials for layer 44 include spin-on-glass, polyimide andbottom anti-reflective coating (BARC) materials such as 0.65 μm grade AZBarli. Accordingly, layers 42 and 44 comprise two layers which areformed over conductor 30 and which are different from one another, witha first of the layers ideally being an insulative or dielectric materialand a second of the layers ideally comprising a BARC material.

Referring to FIG. 5, a layer of photoresist 46 is deposited andpatterned to define a mask opening 48 having a lateral width dimension Wwhich, in the illustrated example, is the same size and in the samewidth dimension direction of the conductor's width dimension W. The maskopening lateral width dimension can, however, vary in width dimensionrelative to the conductor's width dimension. As shown, mask opening 48is misaligned to the left relative to target surface 32 of underlyingconductor 30. Such would, in the prior art, typically cause theresultant contact etch to short to layers underlying the substratebecause the etch would extend over the boundary of the conductor.

Referring to both FIGS. 6 and 7, mask opening 48 becomes contact opening48 through layers 42, 44 to conductor outer target surface 32. In apreferred implementation, second layer material 44 is etched orotherwise removed at a slower rate than the rate at which first layermaterial 42 is removed. Such is evident from FIG. 7 where t₁ illustratesthe removed portion of second layer 44 and t₂ illustrates the removedportion of first layer 42. For example, at the beginning of the etch,only portions of layer 44 are removed. Such corresponds to the FIG. 6construction. Upon outward exposure of underlying layer 42 material,such material begins to be cleared over outer surface 32 (FIG. 7). Inthe illustrated example, as layer 42 material is cleared from atop outersurface 32, layer 44 material continues to be removed. Upon outwardexpose of outer surface 32 and sufficient over etch, the etching isterminated. As shown, layer 44 material is thicker along sidewall 34 andaccordingly, the etch does not reach the substrate surface. Such enablesa contact mask to be misaligned without having to provide a largercontact pad area to accommodate the same. This is because the materialof layers formed adjacent conductor 30 are etched in a manner whichprevents shorting to the substrate surface located immediatelyelevationally therebelow.

Ideally, portions of first and second layers 42 and 44 are removedthrough at least one anisotropic etch which forms contact opening 48over conductor outer surface 32. Preferably, a singular anisotropicetching step is utilized using a common etch chemistry, in going fromthe FIG. 5 to the FIG. 7 construction. With the preferred materials inmind (oxide material for layer 42 and an organic BARC material for layer44) a suitable etch chemistry includes the following parameters in anApplied Materials AME 5000 processor: CF₄ 20 sccm, CHF₃ 40 sccm, Ar 80sccm, 100 Gauss, 600 Watts, electrode temperature of 20° C., and reactorpressure of 200 mT, with the time parameter being dependent upon thethickness of the films being etched.

Alternately, multiple etching steps and chemistries can be utilized,particularly where additional layers beyond layers 42 and 44 areutilized. For example, a first etch chemistry can be utilized for layer44 which may or may not be selective to underlying layer 42. A secondaryetch chemistry could then be used to etch layer 42 faster than thematerial comprising layer 44. An example chemistry for the secondaryetch would be that described above. In this case, layer 44 materialwould be etched in the first step for a time sufficient to remove itfrom over outer surface 32, but not completely remove it from adjacentthe conductor's sidewall(s).

Accordingly, the need for an over-sized contact pad, such as contact pad15 in FIGS. 2 and 3 is reduced if not eliminated. The preferred BARCmaterial has an additional advantage insofar as its light scatteringproperties are concerned. Specifically, during photoresist exposure adegree of light reflecting from the underlying layers occurs which canenlarge the contact opening. The preferred BARC material reduces lightreflectance which, in turn, serves to maintain a desired contact openingwidth. When the contact mask is misaligned over the sidewalls where theBARC material is thicker, an additional reduction in reflectance occurs,thereby reducing the dimension of the contact opening by pulling backthe overlapped edge. This helps to reduce the effective misalignment ofthe overlapped edge.

The illustrated etch results in a portion of the conductor surface ofsidewall 34 which is elevationally below edge 38 being exposed such thatelectrical connection can be made thereto. At least due to theillustrated mask misalignment, this results in removing first and secondlayer portions at the same time, with second layer material beingremoved at a slower rate than first layer material. In this manner, theconductor is cleared of overlying insulator before layer 44 can becleared along the sidewalls of the conductor. This prevents shorts tothe substrate from the misaligned contact

Referring to FIG. 8, photoresist layer 46 and remaining layer 44 arestripped to accommodate electrical connection of conductor 30 with someother circuit component. Alternately, layer 44 might remain andaccordingly not be sacrificial. A representative application of thisinvention would be for use in connecting a second layer of polysiliconto a first layer of polysilicon on an integrated circuit. For example, aconductive layer of polysilicon could be deposited atop the FIG. 8construction and patterned into a conductive line 50, as shown in FIG.9. A more specific application of this invention would be for use inconnection with processing methods of forming integrated circuitrymemory devices such as DRAMs and SRAMs.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

I claim:
 1. A method of forming a self-aligned contact openingcomprising:forming a conductor over a substrate, the conductor having anouter surface which is generally elevated relative to an immediatelylaterally adjacent substrate surface; forming a first layer over theconductor and the adjacent substrate surface; forming a second layerover the first layer; and removing portions of the first and the secondlayers to form a contact opening over the conductor outer surface, theremoving being conducted to remove second layer material at a slowerrate than first layer material.
 2. The method of forming a self-alignedcontact opening of claim 1, wherein the second layer has a non-uniformelevational thickness relative to the first layer.
 3. The method offorming a self-aligned contact opening of claim 1, wherein the formingof a second layer comprises forming a mound of second layer materialover the conductor.
 4. The method of forming a self-aligned contactopening of claim 1, wherein at least some of the first and second layerportions are removed at the same time.
 5. The method of forming aself-aligned contact opening of claim 1, wherein:the conductor includesat least one sidewall edge which extends between the outer surface andthe adjacent substrate surface; and the forming of a second layercomprises forming a mound of second layer material over the conductor.6. The method of forming a self-aligned contact opening of claim 1,wherein the forming of a second layer comprises spin coating the secondlayer onto the substrate.
 7. The method of forming a self-alignedcontact opening of claim 1, wherein the second layer comprises a bottomanti-reflective coating material.
 8. The method of forming aself-aligned contact opening of claim 1, wherein the second layercomprises spin-on-glass.
 9. The method of forming a self-aligned contactopening of claim 1, wherein the second layer comprises polyimidematerial.
 10. The method of forming a self-aligned contact opening ofclaim 1, wherein:the conductor includes at least one sidewall edge whichextends between the outer surface and the adjacent substrate surface;forming a second layer comprises forming a mound of second layermaterial over the conductor; and the second layer comprises a bottomanti-reflective coating material.
 11. The method of forming aself-aligned contact opening of claim 1, wherein:the conductor includesat least one sidewall edge which extends between the outer surface andthe adjacent substrate surface; and the forming of a second layercomprises spin coating the second layer onto the substrate, the secondlayer comprising a bottom anti-reflective coating material.
 12. Themethod of forming a self-aligned contact opening of claim 1, wherein theremoving consists essentially of etching the first and second layerportions using a common etch chemistry.
 13. The method of forming aself-aligned contact opening of claim 1, wherein the removing comprisesetching the first and second layer portions using at least two differentetch chemistries.
 14. The method of forming a self-aligned contactopening of claim 1 further comprising:after the removing of the portionsof the first and second layers, forming conductive material over thesubstrate and in electrical contact with the conductor.
 15. The methodof forming a self-aligned contact opening of claim 1 furthercomprising:after the removing of the portions of the first and secondlayers, removing remaining second layer material; and forming conductivematerial over the substrate and in electrical contact with theconductor.
 16. A method of forming a self-aligned contact openingcomprising:forming a conductor having a conductor target surface and atleast one sidewall joined with the target surface and extendingtransversely away therefrom and toward an adjacent substrate surface;covering the conductor with a dielectric material layer; covering thedielectric material layer with a second material layer which isdifferent from the dielectric material layer; and patterning and etchinga contact opening at least to a portion of the conductor target surface,the etching removing the second layer material at a rate which is slowerthan a rate at which the dielectric layer material is removed.
 17. Themethod of forming a self-aligned contact opening of claim 16, whereinthe second material layer is formed to have a variable elevationalthickness relative to the dielectric material layer.
 18. The method offorming a self-aligned contact opening of claim 16, wherein the secondmaterial layer has an elevational thickness relative to the substratesurface at least a portion of which tapers toward the substrate surfacelaterally outward of the one sidewall.
 19. The method of forming aself-aligned contact opening of claim 16, wherein the covering of thedielectric material layer with the second material layer comprises spincoating second material at least over the dielectric material layerlaterally outward of the one sidewall, the second material layer havingan elevational thickness relative to the substrate surface at least aportion of which tapers toward the substrate surface.
 20. The method offorming a self-aligned contact opening of claim 16, wherein the secondmaterial layer comprises a bottom anti-reflective coating material. 21.The method of forming a self-aligned contact opening of claim 16,wherein:the covering of the dielectric material layer with the secondmaterial layer comprises spin coating second material at least over thedielectric material layer laterally outward of the one sidewall, thesecond material layer having an elevational thickness relative to thesubstrate surface at least a portion of which tapers toward thesubstrate surface, the second material comprising a bottomanti-reflective coating material.
 22. The method of forming aself-aligned contact opening of claim 16, wherein:the step of coveringthe dielectric material layer with the second material layer comprisesspin coating second material at least over the dielectric material layerlaterally outward of the one sidewall; the second material layer havingan elevational thickness relative to the substrate surface at least aportion of which tapers toward the substrate surface, the secondmaterial comprising a bottom anti-reflective coating material; and thepatterning and etching comprising using two different etch chemistriesto remove portions of the second material layer and dielectric layer.23. A method of forming an integrated circuit comprising:forming aconductor over a substrate, the conductor having a generally planarouter surface area supported elevationally outward of a substratesurface; forming at least two layers over the conductor which areetchably different from one another, a first of the layers comprising aninsulative material and a second of the layers comprising a bottomanti-reflective coating (BARC) material; and electrically connecting acircuit component to the conductor through the two layers.
 24. Themethod of forming an integrated circuit of claim 23, wherein the step offorming the second of the layers comprises spin coating the BARCmaterial over the first of the layers to a non-uniform elevationalthickness relative to the first of the layers.
 25. The method of formingan integrated circuit of claim 23, wherein the planar outer surface areais supported by at least one substantially vertical sidewall.
 26. Themethod of forming an integrated circuit of claim 23, wherein the firstof the layers is formed to an elevational thickness over the conductorouter surface area of from about 50 Angstroms to about 5000 Angstroms.27. The method of forming an integrated circuit of claim 23, wherein:thefirst of the layers is formed to an elevational thickness over theconductor outer surface area of from about 50 Angstroms to about 5000Angstroms; and the step of forming the second of the layers comprisesspin coating the BARC material over the first of the layers to anon-uniform elevational thickness relative to the first of the layers.28. A method of forming a conductor assembly through which electricalconnection is to be made comprising:forming a conductive structurehaving at least one abrupt topological feature relative to a laterallyadjacent substrate surface; insulating the conductive structure with agenerally conformal insulative material; forming a generallynon-conformal material over the insulative material, the non-conformalmaterial defining an elevationally variable thickness laterally adjacentthe at least one abrupt topological feature; and electrically connectinga circuit component to the conductor through the generally conformal andnon-conformal materials by removing portions of the insulative materialand the non-conformal material, the non-conformal material being removedat a slower rate than the insulative material.
 29. The method of forminga conductor assembly of claim 28, wherein the generally non-conformalmaterial comprises a bottom anti-reflective coating material.
 30. Themethod of forming a conductor assembly of claim 28, wherein the oneabrupt topological feature is defined in part by a conductive surfacewhich extends generally outwardly of and away from the laterallyadjacent substrate surface.
 31. The method of forming a conductorassembly of claim 28, wherein:the one abrupt topological feature isdefined in part by a conductive surface which extends generallyoutwardly of and away from the laterally adjacent substrate surface; andthe electrically connecting comprises electrically connecting conductivematerial with at least a portion of the conductive surface.
 32. Themethod of forming a conductor assembly of claim 28, wherein the formingof a non-conformal material comprises spin coating the non-conformalmaterial over the insulative material.
 33. A method of forming aself-aligned contact opening comprising:forming a conductor over asubstrate, the conductor having an outer surface which is generallyelevated relative to an immediately laterally adjacent substrate surfaceand which defines a width dimension in a width dimension direction;forming a first electrically insulative layer over the conductor and theadjacent substrate surface; forming a second layer over the first layer;and using a common chemistry removing portions of the first and thesecond layer to form a contact opening over the conductor outer surface,the contact opening having a lateral width dimension in the widthdimension direction which is no less than the lateral width dimension ofthe conductor outer surface, the contact opening not extending to theadjacent substrate surface.
 34. The method of forming a self-alignedcontact opening of claim 33, wherein the second layer is formed from anelectrically insulative material.
 35. A method of forming a self-alignedcontact opening comprising:forming a conductor over a substrate, theconductor having an outer surface disposed between two spaced apartedges, the outer surface being generally elevated relative to animmediately laterally adjacent substrate surface, the conductorincluding at least one other conductor surface elevationally below atleast one of the edges; forming a first layer over the conductor and theadjacent substrate surface; forming a second layer over the first layer;and removing portions of the first and the second layers to form acontact opening over the conductor outer surface, the removing exposingat least a portion of the one other conductor surface elevationallybelow the one edge and forming the contact opening to extend laterallyoutward beyond the one conductor outer surface edge, the contact openingnot extending to the adjacent substrate surface.
 36. The method offorming a self-aligned contact opening of claim 35, wherein the firstand second layers are formed from different materials.
 37. A method offorming a self-aligned contact opening comprising:forming a conductorover a substrate, the conductor having opposing substantially verticalsidewalls which extend elevationally away from the substrate, and agenerally planar target surface disposed laterally adjacent thesidewalls and supported therebetween, the target surface defining aconductor lateral width dimension in a desired width dimensiondirection; forming a generally conformal layer of insulative materialover the substrate and covering the conductor; spin coating a generallynon-conformal layer of bottom anti-reflective coating (BARC) materialover the insulative material, the spin-coating forming a mound of BARCmaterial over the conductor having an elevational thickness relative toa substrate outer surface at least a portion of which tapers toward thesubstrate outer surface laterally away from the conductor targetsurface; and forming a contact opening over less than all of the targetsurface by anisotropically etching portions of the insulative materialand the BARC material which are disposed elevationally over theconductor target surface, the etching removing the insulative materialat a faster rate than the BARC material, at least some of the insulativematerial and the BARC material being removed at the same time, thecontact opening having a contact opening lateral width dimension in thesame desired width dimension direction which is no less than theconductor lateral width dimension, the contact opening extendinglaterally outward beyond one of the conductor opposing sidewalls and notextending to the substrate over which the conductor is formed.
 38. Themethod of claim 37, wherein the spin coating of the non-conformal layercomprises spin coating the layer to be thinner elevationally over theconductor than laterally outward of the conductor.
 39. The method ofclaim 37 further comprising after the forming of the contact opening,removing remaining BARC material and forming conductive material to bein electrical contact with the conductor.
 40. A method of forming aconductor assembly through which electrical connection is to be madecomprising:forming a conductive structure having at least one abrupttopological feature relative to a laterally adjacent substrate surface;insulating the conductive structure with a generally conformalinsulative material; forming a generally non-conformal materialcomprising a bottom anti-reflective coating material over the insulativematerial, the non-conformal material defining an elevationally variablethickness laterally adjacent the at least one abrupt topologicalfeature; and electrically connecting a circuit component to theconductor through the generally conformal and non-conformal materials.